Improvement in heating apparatus for vacuum-pans



B. B. COBB.

HEATING APPARATUS FoRvAcUUM-PAN. 193,488.

Patented July '24, 1877.

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f,... ri fm DELPHIN B. COBB, OF JERSEY CITY, NEW JERSEY, ASSIGNOR OF ONE- HALF HIS RIGHT TO BABCOCK 8U WILCOX, OF NEW YORK, N. Y.

IMPROVEMENT IN HEATING APPARATUS FOR VACUUM-FANS.

Specification forming part of Letters Patent No. 193,@, dated July 24, 1877; application filed July 23, 1875. v

rangement of such chambers, whereby the circulation of the liquid through the apparatus-is facilitated, and the cooler portions being constantly brought in contact with the heating-surface, the efficiency' of the latter is increased.

My invention also involves means for excluding the steam from portions of the apparatus, leaving the action of the remainder evenly distributed through the mass, and allowing the separate use of certain portions of' said apparatus.

The accompanying drawings form a part of this specification, and represent what I consider the best means of carrying out the invention.

Similar letters of reference indicate corresponding parts in the figures.

The drawings represent the novel parts, with so much of the ordinary parts as is necessary to indicate their relations thereto.

Figure l represents a vertical section of` my invention. Fig. 2 is a sectional view of a modiication. Fig. 3 is a horizontal section in plan.

A is the exterior shell or main body of the vacuum-pan. A is a belt or annular chamber cast with or otherwise attached thereto, so as to form, practically, a part of the same. It is divided by a horizontal partition into two halves, the uppermost of which receives steam through a pipe, B1, and the lowermost through a pipe, B2, the low of steam into the upper and lower halves of the belt, respectively, being controlled by the valves b' b2.

Dl Dz are flat thin chambers of sheet copper or other metal, liberally studded or stayed, mounted, respectively, in upright positions,

standing radially, or nearly so, in the vacuumpan A. Suitable inlets for the steam and outlets for water of condensation and air are provided, respectively, at top and lbottom.

The connections from the top of the chamber D1 are marked d1, and communicate with the upper half of the belt A. The upper connections from the chambers I)2 are marked d2, and communicate with the lower half of the belt A. Pipes e communicate with the bottom of each of the dat chambers Dl D2.

rllhe inner edges of the several dat cham-l bers are held accurately in position by the notched hoops or frames Gl G2, in this manner allowing for free radial expansion. The lower of these frames is firmly supported.

lt being understood that the vacuum-pan is provided with a liberal connection at the top, through which the thin vapor is constantly exhausted, and, after being condensed 'in a suitable condenser, pumped 4or drained out, as also with suitable injection cocks and pipes to supply the unconcentrated liquid, and valves and connections at the bottom to dis'- charge it when concentrated.

The action of the apparatus is as follows: The pan being previously filled with thin liquid to a certain height above the heating-surface, steam is admitted into both parts of the belt Af, ows thence through the connections d1 d2 into the radial flat chambers D1 D2, where, after imparting its latent heat to the liquid outside, it is condensed into water, whichis discharged through the pipes e at the bottom. The iiat thin heating-chambers D1 D2 being placed radially, or nearly so, and of uniform width throughout, leave spaces between them which are radial, increasing in width from inward outward like sectors of a circle, and admit of thorough and very perfect circulation of the liquid. y

As soon as heat is applied the portions of' the liquid nearest `to the heating-chambers and the belt Al enter into ebullition, bubbles begin to rise, creating an upward current which is assisted by the liquid expanding and tending also 1to rise. This tends to create a void at the bottom and at the inner edges of the heating-chambers, which void is supplied from the column of cooler and denser liquid always moving down in the free space in. the

center. Sometimes on the louter portions of the chambers, the spaceb'eing greater between them, a column of cooler liquid may tend to go down in the center of that space to rise vagain in contact with the heating-chambers and the belt. Such would but very little interfere with the efficiency of the heating'app'aratus; but 1 prefer that-such counter-currents shall not exist. The belt itself is a very'e'ective heatingsurface, and, in my opinion, adds ma' terially to the good circulation of the liquid by preventing it from going down on the outside and keeping the main circulation central.

My apparatus will work with the steampressure below the pressure of the atmosphere; but for most cases it is preferable to have it a few pounds above.

It may be seen that, with my apparatusf according to the kind of liquid to be evaporated, I can use the whole or portion of thel heating-surface by simply closing one or the other of the controlling-valves; as also, in

case "of accident to any one of the lheatingchambers D*1 D2, I can close the steam-con-v nection to the part of the belt A to whichi such chamber is connected, and continue evaporating with half of the heating-surface. I also provide hand-holes C, closed by hand-hole plates c, opposite each one of 'the steam-inlets d1 d2, so that I can at any 'time open `one of these handholes, plug up the steam-inlet opl posite, and continue working with -the remainder of the heating-surface.

I propose, instead of this, t'o employ, inaddition to the main controlling-valves, further valves, oneeontrolling the 'flow through each pipe at d1 d2. These should be used onlyn vacuum-pans or other evaporating-pans working under conditions where the expense will be warranted. I propose, also, Ito use ares cape pipes to facilitate the escape of air from the chambers DI D, should it be found necessary.

Instead of the divided belt shown in Fig. l, I can realize a part of the advantages by using the single belt with a connection therefrom to each of the radial chambers D1 D. Such case -will require a separate valve for each radial chamber, as shown by b3 in Fig. 2. That figure shows a pipe adapted to allow the discharge of air, there being' one such dis charge-pipe for each valve.

I claim as my inventionl. The radial heating'ichambers, in combination with a central well communicating with .the spaces between the several heating-surfaces, as and for the purposes speciied.

v 2. The steam-distributing belt A',d`ivided into two independent-chambers, supplied with independent `steam-inlets with lmeans for controlling the 'admission of steam, and connected each with alternate "chambers D1 Dz mounted within the evaporating-pan A, as and for the purposes specied.

3. The radial chambers, conformable to the shape of the bottom of the pan for operation and dischargeof the vaenumipan, and extendinginwardlyfrom near the `interior circumference, and having 'a centra-l well, all `in combination with' circumferential Vsteam-belts with steam-connectionsto the radial chambers, fas above described.

In testimony Lvcfhereof I *have herenntoset 'my'hand this `22d day of July', 1875, -in fthe,

presence 'of two subscribing witnesses.

DELPHIN B. COBB. Witnesses:

Hen-nr Gnnrnnn, J. K. OULAHAN. 

